The input field default border styles are coming from Bricks stylesheet. It’s not a setting inside the form element, that’s why no yellow dot indicator.
You are right, the border applied to the submit button as well which is incorrect. Recorded in the bug tracker.
This bug also affects any kind of element that is in the form, like checkboxes.
Border should be applied ideally only to text input fields and all the other form elements have specific settings for border styling-if needed.